CN107112883A - Actuator - Google Patents

Abstract

The actuator (202) has: a rod-shaped inner yoke (1), which is inserted through a cylindrical outer yoke (10); a supporting member, which makes the outer yoke (10) ) supports the outer yoke (10) in such a way that the axial direction of the outer yoke (10) can be freely linearly moved; the first coil (2) and the second coil (3) are wound around the inner yoke (1) with a gap between them and currents flowing in opposite directions; a first magnet array (11), which is disposed on the inner periphery of the outer yoke (10) in a manner facing the first coil (2); and a second magnet array (12) , which is disposed on the inner peripheral portion of the outer yoke (10) in such a way as to face the second coil (3) and has a magnetic pole opposite to that of the first magnet array (11).

Description

actuator

technical field

The present invention relates to an actuator, and more particularly to a linear actuator mounted on a robot or the like for component assembly.

Background technique

Conventionally, an end effector is attached to the tip of a robot to perform various tasks such as component assembly, and as an actuator for driving the end effector, a linear actuator in which the movable part moves linearly relative to the fixed part is sometimes used device.

A so-called "direct drive actuator" that directly drives a movable portion without a speed reducer is used for this linear actuator.

Direct drive actuators can perform high-speed and high-precision motion control, and can expand the working range by linking with robots, but on the other hand, there is a problem that it is difficult to reduce size and increase output. In addition, since the weight that can be attached to the tip of the robot is limited, a compact and high-output actuator is required.

As one of direct drive actuators, there is a voice coil motor (Voice Coil Motor, VCM) in which only a coil reciprocates in a strong magnetic field generated by a permanent magnet such as a neodymium magnet. The voice coil motor can design the movable part to be small, but on the other hand, since it is a direct drive motor, there is a problem that the output per unit volume is low.

On the other hand, Patent Document 1 and Patent Document 2 disclose linear motors in which a plurality of voice coil type linear motor units are arranged side by side. With this structure, the linear motors of Patent Document 1 and Patent Document 2 achieve high output while suppressing volume increase.

prior art literature

patent documents

Patent Document 1: Japanese Unexamined Patent Publication No. 2004-282833

Patent Document 2: Japanese Patent No. 3683199

Contents of the invention

The technical problem to be solved by the invention

The linear motor of Patent Document 1 will be described with reference to FIGS. 8 and 9 . In the linear motor of Patent Document 1, two inner yokes 20 a and 20 b are arranged side by side. The first coils 22a, 22b and the second coils 23a, 23b are wound around the inner yokes 20a, 20b with gaps 21a, 21b provided therebetween.

The inner yokes 20a, 20b are inserted through the first outer yokes 30a, 30b facing the first coils 22a, 22b. The 1st magnets 31a, 31b are provided in the inner peripheral part of the 1st outer yoke 30a, 30b. The two first outer yokes 30a and 30b are fixed in a state of being magnetically connected to each other.

The inner yokes 20a, 20b are inserted through the second outer yokes 32a, 32b that face the second coils 23a, 23b. The second magnets 33a, 33b are provided on the inner peripheral portions of the second outer yokes 32a, 32b. The two second outer yokes 32a and 32b are fixed in a state of being magnetically coupled to each other.

The first outer yokes 30a, 30b and the second outer yokes 32a, 32b are connected by four connecting parts 34 .

Here, the magnetic poles of the first magnet 31a and the second magnet 33b and the magnetic poles of the first magnet 31b and the second magnet 33a are made to be opposite to each other. Moreover, the electric current which flows into the 1st coil 22a and the 2nd coil 23b and the electric current which flow into the 1st coil 22b and the 2nd coil 23a are mutually reversed.

In the linear motor of Patent Document 1, when the first magnets 31a, 31b approach the second coils 23a, 23b due to the influence of leakage flux from the side surfaces of the magnets, a repulsive force is generated, and when the second magnets 33a, 33b approach When the first coils 22a and 22b, a repulsive force is generated. Due to this repulsive force, there is a problem that the linearity of the thrust generation characteristic (hereinafter referred to as “thrust linearity”) with respect to an input current or the position of the movable portion in the axial direction deteriorates.

In addition, in order to suppress the influence of the repulsive force, it is necessary to increase the gaps 21a, 21b between the first coils 22a, 22b and the second coils 23a, 23b. Therefore, there is a problem that the movable range of the movable part including the first outer yokes 30a, 30b and the second outer yokes 32a, 32b is limited, or the inner yokes 20a, 20b are enlarged.

Furthermore, in the linear motor of Patent Document 1, since the main magnetic circuits φ1 and φ2 are formed by the adjacent two first outer yokes 30a, 30b and the adjacent two second outer yokes 32a, 32b, it is not necessary to separately The yoke used to return the magnetic flux (the so-called "return yoke") can be downsized compared with a general linear motor, but the width is doubled compared to a linear motor using a single inner yoke. There is a problem that the linear motor cannot be sufficiently miniaturized.

In addition, as in Patent Document 1 and Patent Document 2, two inner yokes are accommodated in a bottomed box-shaped fixed table, and the outer yoke is freely moved in a straight line through a slider provided in the opening of the fixed table. In the case of a structure in which the outer yoke is movably supported (so-called "outer bearing structure"), there is a problem that the size of the linear motor is further increased.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a more compact and efficient actuator.

Technical means to solve technical problems

The present invention relates to an actuator comprising: a rod-shaped inner yoke inserted through a cylindrical outer yoke; and a support member for freeing the outer yoke along the axial direction of the inner yoke. The outer yoke is supported in a linear motion; the first coil and the second coil are wound around the inner yoke with a gap between them, and currents in opposite directions flow through each other; the first magnet and the second coil are 1. The coil is disposed on the inner periphery of the outer yoke so as to face the second coil; and the second magnet is disposed on the inner periphery of the outer yoke so as to face the second coil, and has magnetic pole.

Invention effect

According to the present invention, a more compact and efficient actuator can be obtained.

Description of drawings

FIG. 1 is an exploded perspective view of an actuator according to Embodiment 1 of the present invention.

Fig. 2 is a perspective view of the actuator according to Embodiment 1 of the present invention.

FIG. 3 is a cross-sectional view along the AB-C-D plane of the actuator shown in FIG. 2 .

Fig. 4 is a perspective view of a fixing unit according to Embodiment 1 of the present invention.

5 is a perspective view of a movable portion according to Embodiment 1 of the present invention.

6( a ) is a characteristic diagram showing the magnitude of the magnetic flux density with respect to the axial coordinates of the actuator according to Embodiment 1 of the present invention; FIG. 6( b ) is a diagram showing an embodiment of the present invention. 1 is an explanatory diagram of the distribution of the magnetic flux density of the actuator.

(a) of FIG. 7 is an explanatory diagram showing the movable range of the actuator according to Embodiment 1 of the present invention; (b) of FIG. Explanatory diagram of the range of motion.

FIG. 8 is a perspective view of a linear motor of Patent Document 2. FIG.

FIG. 9 is an explanatory diagram showing the distribution of the magnetic flux density of the linear motor of Patent Document 2. FIG.

Fig. 10 is an exploded perspective view of an actuator according to Embodiment 2 of the present invention.

Fig. 11 is a perspective view of an actuator according to Embodiment 2 of the present invention.

detailed description

Hereinafter, in order to explain this invention in detail, the form for implementing this invention is demonstrated based on drawing.

Implementation mode 1.

An actuator according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 5 .

In the figure, 1 is the center yoke (inner yoke). The center yoke 1 is composed of a substantially rod-shaped magnetic body.

The first coil 2 and the second coil 3 are wound around the center yoke 1 with a gap between them. The first coil 2 and the second coil 3 are connected in series or in parallel to a current source (not shown), and currents in opposite directions flow therethrough.

A third coil 4 is wound in a gap between the first coil 2 and the second coil 3 . The third coil 4 is connected to a current source via a switching control unit (not shown), and independently of the first coil 2 and the second coil 3 , freely switches the direction of the current flowing therethrough.

A hollow bearing portion 5 is formed along the axis of the center yoke 1 . Bearing members 6 a and 6 b are inserted through both ends of the bearing portion 5 , respectively. A shaft 7 that is thinner and longer than the center yoke 1 is inserted through the hollow portions of the bearing members 6a and 6b. The shaft 7 is supported so that it can move linearly in the axial direction relative to the center yoke 1 and can rotate or not rotate around the shaft.

Here, the bearing members 6a and 6b are constituted by ball bushes or the like when freely rotatable, and are constituted by spline nuts or the like so as not to rotate. Between the center yoke 1 and the shaft 7, thermal separation is carried out by the support part which the bearing member 6a, 6b has.

A top bridge (first bridge) 8 is fitted to one end of the shaft 7 and fixed. The bottom bridging portion (second bridging portion) 9 is fitted and fixed to the other end portion of the shaft 7 . The top bridging portion 8 and the bottom bridging portion 9 have four arm portions 82 , 92 extending in opposite directions from the top ends of the substantially cross-shaped main body portions 81 , 91 . The shaft 7 , the top bridge 8 and the bottom bridge 9 form a so-called "middle bearing construction" bearing component.

An outer yoke (outer yoke) 10 is fixed between the tip end portions of the arm portion 82 of the top bridge portion 8 and the tip end portion of the arm portion 92 of the bottom bridge portion 9 . That is, the outer yoke 10 is supported so as to freely move linearly and freely rotate or not to rotate relative to the center yoke 1 . The outer yoke 10 is composed of a substantially cylindrical magnetic body.

In addition, the shape of the main body parts 81 and 91 is not limited to the cross shape, and the number of the arm parts 82 and 92 is not limited to four. As long as the top bridge 8 and the bottom bridge 9 support the outer yoke 10 so that the outer yoke 10 can move linearly at least, any shape can be used.

On the inner peripheral portion of one end portion of the outer yoke 10 , a first magnet array (first magnet) 11 is provided over the entire circumference. The first magnet array 11 is composed of a plurality of permanent magnets. The first magnet array 11 faces the first coil 2 with a gap therebetween. In addition, the first magnet array 11 also faces the third coil 4 according to the linear motion position of the outer yoke 10 .

On the inner peripheral part of the other end part of the outer yoke 10, the 2nd magnet array (2nd magnet) 12 is provided over the whole circumference. The second magnet array 12 is composed of a plurality of permanent magnets. The second magnet array 12 faces the second coil 3 with a gap therebetween. In addition, the second magnet array 12 also faces the third coil 4 according to the linear motion position of the outer yoke 10 .

Here, the first magnet array 11 and the second magnet array 12 have mutually opposite magnetic poles. For example, the first magnet array 11 has an N pole on the side of the contact surface with the outer yoke 10 , and has an S pole on the side of the surface facing the first coil 2 and the third coil 4 . On the other hand, the second magnet array 12 has an S pole on the side of the contact surface with the outer yoke 10 , and has an N pole on the side of the surface facing the second coil 3 and the third coil 4 .

A flange-shaped bottom plate 13 is fixed to one end of the center yoke 1 . Four through-holes 131 are provided in the bottom plate 13 , and the arm portions 92 of the bottom bridging portion 9 are respectively slidably inserted through the through-holes 131 .

A bottomed cylindrical mounting jig 14 is fixed to the bottom plate 13 so as to cover the bottom bridging portion 9 . The bottom portion 141 of the attachment jig 14 is formed so as to be freely attached to an external device such as a tip portion of a robot for component assembly.

The fixed portion 200 is constituted by the center yoke 1 , the first coil 2 , the second coil 3 , the third coil 4 , the bearing members 6 a , 6 b , the base plate 13 , and the mounting jig 14 . The movable part 201 is constituted by the shaft 7 , the top bridge part 8 , the bottom bridge part 9 , the outer yoke 10 , the first magnet array 11 and the second magnet array 12 . The actuator 202 is constituted by the fixed part 200 and the movable part 201 .

Next, the distribution of the magnetic flux density of the actuator 202 will be described with reference to FIG. 6 .

(a) of FIG. 6 is a characteristic diagram showing magnitudes of magnetic flux densities generated by the first magnet array 11 and the second magnet array 12 with respect to the axial position coordinates of the movable portion 201 . (b) of FIG. 6 shows the magnetic flux φ formed by the first magnet array 11 and the second magnet array 12 in the cross section of the actuator 202 along the AB-CD plane of FIG. 2 .

As shown in FIG. 6( b ), the magnetic flux φ formed by the first magnet array 11 and the second magnet array 12 is a loop-shaped magnetic flux passing through the entire circumference of the outer yoke 10 and inside the center yoke 1 .

In a general voice coil motor, in order to form a loop-shaped magnetic flux, a return yoke for returning the magnetic flux is provided separately from the center yoke 1 and the outer yoke 10 . The actuator 202 according to Embodiment 1 has a structure in which two motors are connected in series, and since the magnetic flux is returned by the center yoke 1 and the outer yoke 10 , the return yoke can be unnecessary. With this configuration, the actuator 202 can be miniaturized.

Moreover, by providing the first magnet array 11 and the second magnet array 12 over the entire circumference of both ends of the outer yoke 10, the entire circumference of the outer yoke 10 can be used as a magnetic circuit, thereby reducing magnetic resistance. Therefore, the thickness of the outer yoke 10 can be reduced, and the weight of the actuator 202 can be reduced.

Furthermore, since the central portion of the center yoke 1 has a low magnetic flux density, its contribution to the formation of the magnetic circuit is small. Therefore, even if the hollow bearing portion 5 is provided on the axis of the center yoke 1, the efficiency of the actuator 202 does not decrease so much. Therefore, by adopting the middle bearing structure composed of the shaft 7, the top bridging portion 8, and the bottom bridging portion 9, compared with the conventional linear motor using the outer bearing structure composed of the fixed table and the slider, the efficiency can be reduced. Achieve miniaturization.

Next, the movable range of the linear motion operation of the actuator 202 will be described with reference to FIGS. 6 and 7 .

As shown in (a) of FIG. 6 , due to the magnetic flux leaking from the side of the first magnet array 11, the axial position coordinates are in the range of about -10 to -6 millimeters (mm) and about +6 to +10 mm The magnitude of the magnetic flux density within the range increases to about 0.05-0.5 Tesla (T). Similarly, due to the magnetic flux leaked from the side of the second magnet array 12, the axial coordinates are in the range of about +18 to +22 mm and the magnitude of the magnetic flux density in the range of about +34 to +38 mm increases to About 0.05～0.5T.

In FIG.7(b), the movable range of the actuator which does not have the 3rd coil 4 shown in FIGS. 1-5 is shown as a comparative object. Corresponding to the linear motion action of the actuator, when the first magnet array 11 is close to the second coil 3, due to the magnetic flux leaked from the side of the first magnet array 11, there will be a gap between the first magnet array 11 and the second coil 3. 3 generate axial repulsion. Similarly, when the second magnet array 12 is close to the first coil 2, due to the magnetic flux leaked from the side of the second magnet array 12, an axial repulsive force is generated between the second magnet array 12 and the first coil 2. .

Generally, the first coil 2 and the second coil 3 are connected in series or in parallel to the same current source, and the directions of the flowing currents cannot be controlled independently of each other. Therefore, especially at the position where the first magnet array 11 is close to the second coil 3 and the position where the second magnet array is close to the first coil 2 , the thrust linearity of the actuator deteriorates due to the repulsive force.

In addition, in order to reduce the influence of the repulsive force, it is necessary to widen the width between the first coil 2 and the second coil 3 to such an extent that the influence does not become a practical problem. This restricts the movable range of the movable portion 201 or increases the size of the fixed portion 200 .

On the other hand, the actuator 202 according to Embodiment 1 is provided with the third coil 4 between the first coil 2 and the second coil 3 as shown in FIG. 7( a ). Here, if L represents the distance along the axial direction between the first magnet array 11 and the second magnet array 12, and P represents the magnetic flux due to leakage from one side of the first magnet array 11 and the second magnet array 12. As for the width along the axial direction of the region where the repulsive force is generated, the width along the axial direction of the third coil 4 is set to L−2P.

When the first magnet array 11 approaches the third coil 4 from the first coil 2 side and the width between the first magnet array 11 and the third coil 4 becomes equal to or less than a predetermined value (in the example of FIG. When the distance between the first magnet array 11 and the third coil 4 becomes equal to the distance between the second magnet array 12 and the third coil 4), the switching control part (not shown) will flow through the third coil 4. The direction of the current is switched to the same direction as the direction of the current flowing through the first coil 2 . Accordingly, the outer yoke 10 can move the first magnet array 11 to a region facing the third coil 4 while suppressing the repulsive force between the first magnet array 11 and the second coil 3 .

On the other hand, when the second magnet array 12 approaches the third coil 4 from the second coil 3 side and the width between the second magnet array 12 and the third coil 4 becomes below a predetermined value (in the example of FIG. , when the distance between the second magnet array 12 and the third coil 4 becomes equal to the distance between the first magnet array 11 and the third coil 4), the unshown switching control unit will switch between the third coil The direction of the current flowing in 4 is switched to the same direction as the direction of the current flowing in the second coil 3 . Accordingly, the outer yoke 10 can move the second magnet array 12 to a region facing the third coil 4 while suppressing the repulsive force between the second magnet array 12 and the first coil 2 .

In this way, the direction of the current flowing through the third coil 4 is switched according to the axial position of the outer yoke 10 , so that the movable range of the outer yoke 10 in the linear motion direction can be widened. The movable range X2 of the actuator 202 according to Embodiment 1 shown in FIG. 7( a ) is wider than the movable range X1 of the comparison actuator shown in FIG. ΔX.

As described above, the actuator 202 according to Embodiment 1 includes: one rod-shaped center yoke 1 inserted through one cylindrical outer yoke 10; The outer yoke 10 is supported in such a way that the axial direction of the yoke 1 can move freely in a straight line; the first coil 2 and the second coil 3 are wound around the center yoke 1 with a gap between them and flow through mutually opposite coils. Current; the first magnet array 11, which is provided on the inner peripheral portion of the outer yoke 10 so as to face the first coil 2; and the second magnet array 12, which is provided on the The inner peripheral portion of the outer yoke 10 has a magnetic pole opposite to that of the first magnet array 11 . With this structure, while improving the operating efficiency of the actuator 202, it is possible to obtain a more compact actuator 202 because the return yoke is unnecessary.

In addition, the first magnet array 11 is provided over the entire inner circumference of one end of the outer yoke 10 , and the second magnet array 12 is provided over the entire inner circumference of the other end of the outer yoke 10 . With this configuration, the entire circumference of the outer yoke 10 is used as a magnetic circuit, thereby making it possible to reduce magnetic resistance.

In addition, the actuator 202 has a hollow bearing portion 5 along the axis of the center yoke 1 . The support member is connected by a shaft 7 inserted through the bearing portion 5 and supported so as to be free to linearly move relative to the center yoke, and a top bridge fitted to one end of the shaft 7 and abutting on one end of the outer yoke 10 . part 8 and the bottom bridging part 9 which fits the other end part of the shaft 7 and abuts against the other end part of the outer yoke 10 . With this structure, it is possible to achieve downsizing compared with a conventional linear motor employing an outer bearing structure without affecting the operating efficiency.

In addition, the actuator 202 has a third coil 4 wound between the first coil 2 and the second coil 3, and the direction of the current flowing through the third coil 4 is switched according to the axial position of the outer yoke 10. switching control unit. When the distance between the first magnet array 11 and the third coil 4 becomes below a predetermined value, the switching control unit switches the direction of the current of the third coil 4 to the same direction as that of the first coil 2, and when the second magnet array 11 When the distance between 12 and the third coil 4 becomes equal to or less than a predetermined value, the direction of the current of the third coil 4 is switched to the same direction as that of the second coil 3 . Accordingly, the movable range of the outer yoke 10 in the linear motion direction can be widened. In addition, the thrust linearity of the actuator 202 can be improved.

In addition, the supporting member supports the outer yoke 10 so that the outer yoke 10 can freely rotate or not rotate with respect to the axis of the center yoke 1 . Thus, a compact actuator 202 with two degrees of freedom can be obtained.

In addition, the cross-sectional shapes of the center yoke 1 and the outer yoke 10 are not limited to circular shapes. In particular, when the outer yoke 10 is supported so that the outer yoke 10 does not rotate, the cross-sectional shape may be a quadrangular shape or a triangular shape.

Implementation mode 2.

Referring to FIG. 10 and FIG. 11 , an actuator in which structural strength has been further improved in addition to being compact and highly efficient as in Embodiment 1 will be described. In addition, in FIGS. 10 and 11 , the same components as those of the actuator of Embodiment 1 shown in FIGS. 1 to 5 are assigned the same reference numerals, and description thereof will be omitted.

Two cylindrical support portions 132 a and 132 b facing each other are rotatably attached to the through hole 131 of the bottom plate 13 . The arm portion 92 of the bottom bridge portion 9 is formed in a substantially cylindrical shape, and is inserted and penetrated between the support portions 132a, 132b.

Thus, the arm portion 92 of the bottom bridge portion 9 functions to support the shaft of the movable portion 201 so that the movable portion 201 can freely move linearly relative to the fixed portion 200 . The movable part 201 is supported by two shafts, namely the shaft 7 inserted through the center yoke 1 and the arm part 92 inserted through between the support parts 132a and 132b. Compared with the structure using only one shaft 7, The structural strength of the actuator 202 can be improved.

In addition, the width between the two support portions 132a and 132b is set to be slightly larger than the diameter of the arm portion 92 (for example, about 20 μm). As a result, a gap is formed between the arm portion 92 and the support portions 132 a and 132 b in a state where no force (hereinafter referred to as “torsion load”) is applied to rotate the movable portion 201 relative to the fixed portion 200 about the shaft 7 . On the other hand, in a state where a torsional load is applied, the arm portion 92 abuts against one of the two support portions 132a, 132b, thereby restricting the rotation of the movable portion 201 relative to the fixed portion 200 .

In Embodiment 1, when ball splines are used for the bearing members 6a and 6b, the strength of the actuator 202 against torsional load (hereinafter referred to as “torsion resistance strength”) depends on the shaft 7 and the bearing members 6a and 6b. to determine the critical value. Therefore, in Embodiment 1, for example, by making the shaft 7 thinner, it is conceivable to suppress the reduction in the volume of the center yoke 1 and to realize miniaturization and high efficiency of the actuator 202. However, in this case, the shaft 7 The critical value of becomes lower and the torsional strength of the actuator 202 decreases.

Therefore, when a torsional load is applied to the actuator 202 of the second embodiment, the arm portion 92 abuts against the support portions 132a, 132b, the rotation of the movable portion 201 is restricted, and the shaft 7 is moved relative to the bearing members 6a, 6b. The rotation angle is suppressed within the allowable range. That is, the width between the two support portions 132a, 132b is set so that the rotation angle of the shaft 7 is suppressed within the allowable range when the arm portion 92 abuts against the support portions 132a, 132b in accordance with the rotation of the outer yoke 10. width. Thereby, the torsional strength of the actuator 202 can be improved, and the problem in the case of making the shaft 7 thinner as described above can also be solved.

As described above, the actuator 202 according to Embodiment 2 includes the bottom plate 13 provided at the other end portion of the center yoke 1 , and the support portions 132 a and 132 b arranged to face the through-hole 131 of the bottom plate 13 . The bottom bridging portion 9 has a main body 91 fitted to the other end of the shaft 7 and an arm 92 extending from the main body 91 and abutting against the other end of the outer yoke 10, and the arm 92 is inserted through the supporting portion 132a. , 132b. Since the arm portion 92 functions as a shaft, the strength of the actuator 202 can be increased compared to a configuration using only one shaft 7 .

In addition, gaps are formed between the arm portion 92 and the support portions 132a, 132b. The width between the support portions 132a, 132b is set to a width that suppresses the rotation angle of the shaft 7 within an allowable range when the arm portion 92 contacts the support portions 132a, 132b in accordance with the rotation of the outer yoke 10 . Accordingly, the torsional strength of the actuator 202 can be improved while reducing the volume of the center yoke 1 by making the shaft 7 thinner.

In addition, the arm portion of the bridge portion functioning as a shaft is not limited to any one of the four arm portions 92 included in the bottom bridge portion 9 . It is also possible to install the supporting parts 132a, 132b to a plurality of through holes among the four through holes 131 provided on the bottom plate 13, so that a plurality of the four arm parts 92 of the bottom bridging part 9 can be used as axes. Function.

Alternatively, a bottom plate may be provided at the end of the center yoke 1 on the top bridge 8 side, and a through hole and a support portion may be provided on the bottom plate so that the arm portion of the top bridge 8 functions as a shaft.

In addition, the member functioning as a shaft is not limited to the arm portion of the bridge portion. As long as the rotation of the movable part 201 can be restricted when a torsional load is applied to the actuator 202, the support part can also be installed on the hole provided by any member of the fixed part 200, and any part of the movable part 201 Components are inserted through.

In addition, the mechanism which supports the arm part which functions as a shaft is not limited to the two support part 132a, 132b shown in FIG.10 and FIG.11. Any mechanism can be used as long as it supports the arm at two points.

In addition, within the scope of the invention, the invention of the present application can freely combine the respective embodiments, modify arbitrary components of the respective embodiments, or omit arbitrary components in the respective embodiments.

Industrial availability

The actuator of the present invention can be attached to a robot or the like for component assembly and used.

Symbol Description

1 Center yoke (inner yoke)

2 1st coil

3 2nd coil

4 3rd coil

5 Bearing

6a, 6b Bearing components

7 axis

8 Top bridge (1st bridge)

9 Bottom bridge (2nd bridge)

10 Outer yoke (outer yoke)

11 1st magnet array (1st magnet)

12 2nd magnet array (2nd magnet)

13 Bottom plate

14 Mounting fixture

20a, 20b inner yoke

21a, 21b clearance

22a, 22b 1st coil

23a, 23b 2nd coil

30a, 30b 1st outer yoke

31a, 31b first magnet

32a, 32b 2nd outer yoke

33a, 33b 2nd magnet

34 Connecting part

81 Main body

82 arm

91 Main body

92 arm

131 through hole

132a, 132b support portion

141 Bottom

200 fixed part

201 Movable parts

202 actuator.

Claims (9)

1. An actuator, characterized in that it possesses: A rod-shaped inner yoke inserted through a cylindrical outer yoke; a supporting member that supports the outer yoke in such a manner that the outer yoke can freely perform rectilinear movement along the axial direction of the inner yoke; The first coil and the second coil are wound around the inner yoke with a gap between them, and currents in opposite directions flow therethrough; a first magnet provided on an inner peripheral portion of the outer yoke so as to face the first coil; and The second magnet is provided on the inner peripheral portion of the outer yoke so as to face the second coil, and has a magnetic pole opposite to that of the first magnet. 2. The actuator of claim 1 wherein, The first magnet is provided over the entire inner circumference of one end of the outer yoke, The second magnet is provided over the entire inner circumference of the other end of the outer yoke. 3. The actuator of claim 1 wherein, having a hollow bearing portion along the axis of the inner yoke, The support member has: a shaft inserted through the bearing portion and supported so as to be free to linearly move relative to the inner yoke; a first bridging portion fitted to one end of the shaft and abutted against one end of the outer yoke; and The second bridging portion is fitted to the other end of the shaft and is in contact with the other end of the outer yoke. 4. The actuator according to claim 1, characterized in that it has: a third coil wound between the first coil and the second coil; and The switching control unit switches the direction of the current flowing through the third coil according to the axial position of the outer yoke. 5. Actuator according to claim 4, characterized in that, The switching control unit switches the direction of the current of the third coil to the same direction as that of the first coil when the distance between the first magnet and the third coil becomes equal to or smaller than a predetermined value, and When the distance between the second magnet and the third coil becomes equal to or smaller than a predetermined value, the direction of the current of the third coil is switched to the same direction as that of the second coil. 6. The actuator of claim 1 wherein, The supporting member supports the outer yoke so that the outer yoke can freely rotate with respect to the axis of the inner yoke. 7. The actuator of claim 1 wherein, The cross section of the outer yoke is circular, quadrangular or triangular in shape, A cross section of the inner yoke is a circular shape, a quadrangular shape or a triangular shape. 8. The actuator according to claim 3, characterized in that it has: a bottom plate provided at the other end of the inner yoke; and the supporting portion is disposed opposite to the through hole of the bottom plate, The second bridging portion has a main body fitted to the other end of the shaft, and an arm extending from the main body and abutting against the other end of the outer yoke, The arm part is inserted through between the supporting parts. 9. The actuator of claim 8, wherein a gap is formed between the arm portion and the support portion, The width between the support portions is set to be such that when the arm portion comes into contact with the support portion in accordance with the rotation of the outer yoke, the rotation angle of the shaft is suppressed within an allowable range.